为探讨流动温压工艺对铁基粉末成形的效果,采用自行设计的流动温压测试系统,研究了雾化铁粉与细羰基铁粉的混合粉末的流动温压行为.研究显示：与常温压制相比,流动温压过程中的侧压力随横向距离的增加下降趋势更为缓慢,特别是在常规粉末成形压力600～700MPa下具有比常温压制更高的侧压系数,即在相同位置处具有更高的侧压力和致密度;以聚乙二醇（PEG）作为铁粉的粘结剂时,最佳压制温度、压制速度分别为62℃、240mm/min,适宜的PEG含量为2%～3%;在流动温压条件下,粘结剂将金属粉末包覆并粘结在一起,改善了金属粉末的填充能力,并提高了润滑膜的承载能力,从而改善了粉末的压力传递效果,可成形形状较为复杂且具有较高致密度的粉末冶金零件.

In order to explore the effect of warm flow compaction on the forming process of iron-based powders,the behaviors of warm flow compaction of the mixture of atomized iron powders and fine ferrocarbonyl powders are analyzed by using a self-developed testing system.By comparing the room-temperature compaction with the warm flow compaction,it is found that the decrease rate of lateral pressure in the warm flow compaction with the increase of transverse distance is slow,especially,at general powder-forming pressure of 600～700MPa,warm flow compaction is of higher lateral pressure coefficient than room-temperature compaction.This means that,in the same position in a part,warm flow compaction yields higher lateral pressure and relative density.It is also found that,for polyethylene glycol（PEG） binder,the optimal compaction temperature and speed are respectively 62℃ and 240mm/min,and the suitable PEG content ranges from 2% to 3%;and that,during the warm flow compaction,binder sufficiently coats and bonds metal powders,thus improving the filling capability of powders and the supportability of binder lubrication film.As a result,the pressure transmission effect among powders becomes better,and powder metallurgy part with complicated shape and high relative density can be successfully obtained.